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<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>
    <script>
        //变量
        let name = "jack"
        let age = 10

        name = "bit"
         age = 12


        //常量
        const PI= 3.14
        PI= 3.1415926
        
        
/*         const arr = [1,2,3]
       //添加属性
        arr.push(4)
        console.log(arr)
        
        arr.shift()
        console.log(arr) */
        
    </script>
</body>
</html>